The present invention relates to a process for the production of expanded polyester, in particular PET for the production of articles such as, for example, panels, sheets and tubes, which can be used in particular in the building and packaging field.
The object of the present invention is to provide a process of the above indicated type which will allow the production of an expanded product of adequate characteristics for the above listed uses. This involves, in particular, obtaining a final product of density at least to 40 kg/m3, uniform cellular structure of fine cells, and without degradations evidenced by reductions in molecular weight and viscosity with respect to the starting product, which are due for example to possible hydrolysis reactions.
According to the invention this object is achieved by a process and apparatus for its performance having the characteristics specifically set out in the following claims.